Fatal Pneumonia and Pleuritis Caused by an Agujon Beak Penetration in a Bottlenose Dolphin from Puerto Rico

Abstract

Although wounds caused by fish spines have been reported to cause disease and mortality in marine mammals, no record of this phenomenon exists for the Caribbean area. We report a case of disease and consequent mortality in a bottlenose dolphin Tursiops truncatus caused by ingestion of the beak of an agujon Tylosurus acus in Manatí, Puerto Rico. Internal examination of the dolphin revealed that its left lung was necrotic and reduced to one-fourth its normal size and that it had chronic–active pleural inflammation. A 9.1-cm compound bone fragment was found embedded in an abscess in the pleural lining of the left lung. The bone fragment was identified as belonging to the jaws of an agujon, a circumtropical, polytypic species commonly found in the Caribbean Sea. Histopathology revealed chronic inflammation and fibrosis of the lung in addition to granulomatous masses in the pleural space. The cause of death was determined to be chronic lung infection caused by migration of the agujon's beak from the dolphin's esophagus or stomach. No similar cases have been observed in the more than 150 marine mammal strandings documented in Puerto Rico and the Virgin Islands since 1985. This is the first report of disease and death caused by migration of an agujon beak in a marine mammal.